一項研究說，果蠅攜帶的共生細菌可以影響果蠅的交配偏好,。進化論認為,，進化的引擎——自然選擇不僅對生物的基因起作用，也對生物攜帶的任何共生微生物的基因起作用,。為了確定共生細菌是否影響果蠅的交配偏好并驅動著進化,，Eugene Rosenberg及其同事用果蠅進行了交配偏好的測試，這些果蠅是在含有糖漿或淀粉的食物源中喂養(yǎng)的,。這組作者報告說,，在經過一代的生長后，喂養(yǎng)糖漿的果蠅更喜歡與同類果蠅交配,，而不是與淀粉喂養(yǎng)的果蠅交配,。
這組作者發(fā)現(xiàn)，這種偏好至少持續(xù)了37代,，但是讓果蠅服用抗生素從而殺死它們的共生細菌的時候,，這種偏好終止了，這提示這種細菌而非食物源驅動著這種偏好,。通過解讀這種細菌的遺傳藍圖,，這組作者確定了植物乳桿菌（Lactobacillus plantarum）是這種交配偏好的部分觸發(fā)原因。此外,，這種細菌很可能通過改變果蠅角質層的性激素濃度從而影響了交配偏好,。這組作者說，這些發(fā)現(xiàn)提示共生細菌可能影響交配選擇和物種形成,。（生物谷Bioon.com）
生物谷推薦英文摘要：
PNAS doi: 10.1073/pnas.1009906107
Commensal bacteria play a role in mating preference of Drosophila melanogaster
Gil Sharona, Daniel Segala, John M. Ringob, Abraham Hefetzc, Ilana Zilber-Rosenbergd, and Eugene Rosenberga,1
aDepartment of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel;
bSchool of Biology and Ecology, University of Maine, Orono, ME 04469;
cDepartment of Zoology, Tel Aviv University, Tel Aviv 69978, Israel; and
d18 Rachavat Ilan St., Givat Shmuel 51905, Israel
Development of mating preference is considered to be an early event in speciation. In this study, mating preference was achieved by dividing a population of Drosophila melanogaster and rearing one part on a molasses medium and the other on a starch medium. When the isolated populations were mixed, “molasses flies” preferred to mate with other molasses flies and “starch flies” preferred to mate with other starch flies. The mating preference appeared after only one generation and was maintained for at least 37 generations. Antibiotic treatment abolished mating preference, suggesting that the fly microbiota was responsible for the phenomenon. This was confirmed by infection experiments with microbiota obtained from the fly media (before antibiotic treatment) as well as with a mixed culture of Lactobacillus species and a pure culture of Lactobacillus plantarum isolated from starch flies. Analytical data suggest that symbiotic bacteria can influence mating preference by changing the levels of cuticular hydrocarbon sex pheromones. The results are discussed within the framework of the hologenome theory of evolution.
